The essence of many medical treatments and procedures involves the removal or destruction of harmful or unwanted tissue. Examples of such important treatments include the surgical removal of cancerous growths, the destruction of metatastic tumors through chemotherapy, and the reduction of glandular (e.g. prostate) hyperplasia. Other examples include the removal of unwanted facial hair, warts, subcutaneous tissue, lymphoid tissue or fatty tissue.
There is a need for an effective agent that will destroy and hence either facilitate the removal of or inhibit the further growth of harmful or unwanted cells and tissue, but that will have mainly local effects and minimal or absent systemic toxicity. Neural thread proteins and their related molecules are one class of such agents as disclosed in pending U.S. patent application Ser. No. 10/092,934, entitled: Methods of Treating Tumors and Related Conditions Using Neural Thread Proteins, filed on Mar. 8, 2002, the disclosure of which is incorporated be reference herein in its entirety. Peptides containing amino acid sequences corresponding to part of the amino acid sequence of a neural thread protein, AD7c-NTP also are such agents. These peptides are disclosed in pending U.S. application Ser. No. 10/153,334, entitled: Peptides Effective in the Treatment of Tumors and Other Conditions Requiring the Removal or Destruction of Cells, filed May 24, 2002, the disclosure of which is incorporated by reference herein in its entirety.
Cancer is an abnormality in a cell's internal regulatory mechanisms that results in uncontrolled growth and reproduction of the cell. Normal cells make up tissues, and when these cells lose their ability to behave as a specified, controlled, and coordinated unit (dedifferentiation) the defect leads to disarray amongst the cell population. When this occurs, a tumor is formed.
Benign overgrowths of tissue are abnormalities in which it is desirable to remove cells from an organism. Benign tumors are cellular proliferations that do not metastasize throughout the body but do, however, cause disease symptoms. Such tumors can be lethal if they are located in inaccessible areas in organs such as the brain. There are benign tumors of organs including lung, brain, skin, pituitary, thyroid, adrenal cortex and medulla, ovary, uterus, testis, connective tissue, muscle, intestines, ear, nose, throat, tonsils, mouth, liver, gall bladder, pancreas, prostate, heart, and other organs.
Surgery often is the first step in the treatment of cancer. The objective of surgery varies. Sometimes it is used to remove as much of the evident tumor as possible, or at least to debulk it (remove the major bulk(s) of tumor so that there is less that needs to be treated by other means). Depending on the cancer type and location, surgery also may provide some symptomatic relief to the patient. For instance, if a surgeon can remove a large portion of an expanding brain tumor, the pressure inside the skull will decrease, leading to improvement in the patient's symptoms.
Not all tumors are amenable to surgery. Some may be located in parts of the body that make them impossible to completely remove. Examples of these would be tumors in the brainstem (a part of the brain that controls breathing) or a tumor which has grown in and around a major blood vessel. In these cases, the role of surgery is limited due to the high risk associated with tumor removal.
In some cases, surgery is not used to debulk tumor because it is not necessary. An example is Hodgkin's lymphoma, a cancer of the lymph nodes that responds very well to combinations of chemotherapy and radiation therapy. In Hodgkin's lymphoma, surgery is rarely needed to achieve cure, but almost always used to establish a diagnosis.
Chemotherapy is a common form of cancer treatment that involves the use of medications (usually given by mouth or injection) which specifically attack rapidly dividing cells (such as those found in a tumor) throughout the body. This makes chemotherapy useful in treating cancers that have already metastasized, as well as tumors that have a high chance of spreading through the blood and lymphatic systems but are not evident beyond the primary tumor. Chemotherapy may also be used to enhance the response of localized tumors to surgery and radiation therapy. This is the case, for example, for some cancers of the head and neck.
Unfortunately, other cells in the human body that also normally divide rapidly (such as the lining of the stomach and hair) also are affected by chemotherapy. For this reason, many chemotherapy agents induce undesirable side effects such as nausea, vomiting, anemia, hair loss or other symptoms. These side effects are temporary, and there exist medications that can help alleviate many of these side effects. As our knowledge has continued to grow, researchers have devised newer chemotherapeutic agents that are not only better at killing cancer cells, but that also have fewer side effects for the patient.
Chemotherapy is administered to patients in a variety of ways. Some are pills and some are administered by an intravenous or other injection. For injectable chemotherapy, a patient goes to the doctor's office or hospital for treatment. Other chemotherapeutic agents require continuous infusion into the bloodstream, 24 hours a day. For these types of chemotherapy, a minor surgical procedure may be performed to implant a small pump worn by the patient. The pump then slowly administers the medication. In many cases, a permanent port is placed in a patient's vein to eliminate the requirement of repeated needle sticks.
Radiation therapy is another commonly used weapon in the fight against cancer. Radiation kills cancer by damaging the DNA within the tumor cells. The radiation is delivered in different ways, the most common of which involves pointing a beam of radiation at the patient in a highly precise manner, and focusing on the tumor. To do this, a patient lies on a table and the beam moves around him/her. The procedure lasts minutes, but may be done daily for several weeks (depending on the type of tumor), to achieve a particular total prescribed dose.
Another radiation method sometimes employed, called brachytherapy, involves taking radioactive pellets (seeds) or wires and implanting them in the body in the area of the tumor. The implants can be temporary or permanent. For permanent implants, the radiation in the seeds decays over a period of days or weeks so that the patient is not radioactive. For temporary implants, the entire dose of radiation is usually delivered in a few days, and the patient must remain in the hospital during that time. For both types of brachytherapy, radiation generally is delivered to a very targeted area to gain local control over a cancer (as opposed to treating the whole body, as chemotherapy does.)
Some highly selected patients may be referred for bone marrow transplants. This procedure is usually performed either because a patient has a cancer that is particularly aggressive or because they have a cancer that has relapsed after being treated with conventional therapy. Bone marrow transplantation is a complicated procedure. There are many types, and they vary in their potential for causing side effects and cure. Most transplants are performed at special centers, and in many cases their use is considered investigational.
There are a number of other therapies, though most of them are still being explored in clinical trials and have not yet become standard care. Examples include the use of immunotherapy, monoclonal antibodies, anti-angiogenesis factors, and gene therapy.
Immunotherapy: There are various techniques designed to help the patient's own immune system fight the cancer, quite separately from radiation or chemotherapy. Oftentimes, to achieve the goal researchers inject the patient with a specially derived vaccine. Monoclonal Antibodies: These are antibodies designed to attach to cancerous cells (and not normal cells) by taking advantage of differences between cancerous and non-cancerous cells in their anitgenic and/or other characteristics. The antibodies can be administered to the patient alone or conjugated to various cytotoxic compounds or in radioactive form, such that the antibody preferentially targets the cancerous cells, thereby delivering the toxic agent or radioactivity to the desired cells.
Anti-Angiogenesis Factors: As cancer cells rapidly divide and tumors grow, they can soon outgrow their blood supply. To compensate for this, some tumors secrete a substance believed to help induce the growth of blood vessels in their vicinity, thus providing the cancer cells with a vascular source of nutrients. Experimental therapies have been designed to arrest the growth of blood vessels to tumors.
Gene Therapy: Cancer is the product of a series of mutations that ultimately lead to the production of a cancer cell and its excessive proliferation. Cancers can be treated by introducing genes to the cancer cells that will act either to check or stop the cancer's proliferation, turn on the cell's programmed cell mechanisms to destroy the cell, enhance immune recognition of the cell, or express a pro-drug that converts to a toxic metabolite or a cytokine that inhibits tumor growth.
Benign tumors and malformations also can be treated by a variety of methods including surgery, radiotherapy, drug therapy, thermal or electric ablation, cryotherapy, and others. Although benign tumors do not metastasize, they can grow large and they can recur. Surgical extirpation of benign tumors has all the difficulties and side effects of surgery in general and oftentimes must be repeatedly performed for some benign tumors, such as for pituitary adenomas, meningeomas of the brain, prostatic hyperplasia, and others.
There still other are conditions involving unwanted cellular elements where selective cellular removal is desirable. For example, heart disease and strokes are commonly caused by atherosclerosis, which is a proliferative lesion of fibrofatty and modified smooth muscle elements which distort the blood vessel wall, narrow the lumen, constrict blood flow, predispose to focal blood clots, and ultimately lead to blockage and infarction. Various treatments for atherosclerosis include bypass grafts; artificial grafts; angioplasty with recanalization, curettage, radiation, laser, or other removal; pharmacotherapy to inhibit atherosclerosis through lipid reduction; anti-clotting therapies; and general measures of diet, exercise, and lifestyle. A method for removing atherosclerotic lesions without the risk and side effects of surgical procedures is needed.
Other examples of unwanted cellular elements where selective cellular removal is desirable include viral induced growths, such as warts. Another example is hypertrophic inflammatory masses found in inflammatory conditions, and hypertrophic scars or keloids. Still other examples are found in cosmetic contexts such as the removal of unwanted hair, e.g., facial hair, or for shrinkage of unwanted tissue areas for cosmetic purposes, such as in the facial dermis and connective tissues or in the dermas and connective tissue of the extremities.
Still other examples will be obvious to those of ordinary skill in the art. In all or most of these examples there is a need for treatments that can remove or destroy the unwanted cellular elements without the risks and side effects of conventional therapies and to remove the unwanted cellular elements with more precision.
Neural thread proteins (NTP) are a family of recently characterized brain proteins. One member of this family, AD7c-NTP, is a ˜41 kD membrane associated phosphoprotein with functions associated with neuritic sprouting (de la Monte et al., J. Clin. Invest., 100:3093-3104 (1997); de la Monte et al., Alz. Rep., 2:327-332 (1999); de la Monte S M and Wands J R, Journal of Alzheimer's Disease, 3:345-353 (2001)). The gene that encodes AD7c-NTP and predicted protein sequence for AD7c-NTP has been identified and described (de la Monte et al., J. Clin. Invest., 100:3093-3104 (1997)). In addition to the ˜41 kD species, other species of neural thread protein (˜26 kD, ˜21 kD, ˜17 kD, and ˜15 kD) have been identified and associated with neuroectodermal tumors, astrocytomas, and glioblastomas and with injury due to hypoxia, schema, or cerebral infarction (Xu et al., Cancer Research, 53:3823-3829 (1993); de la Monte et al., J. Neuropathol. Exp. Neurol., 55(10):1038-50 (1996), de la Monte et al., J. Neurol. Sci., 138(1-2):26-35 (1996); de la Monte et al., J. Neurol. Sci., 135(2): 118-25 (1996); de la Monte et al., J. Clin. Invest., 100:3093-3104 (1997); and de la Monte et al., Alz. Rep., 2:327-332 (1999)).
Species of neural thread protein have been described and claimed in U.S. Pat. Nos. 5,948,634; 5,948,888; and 5,830,670, all for “Neural Thread Protein Gene Expression and Detection of Alzheimer's Disease” and in U.S. Pat. No. 6,071,705 for “Method of Detecting Neurological Disease or Dysfunction.” The disclosures of these patents are specifically incorporated herein by reference in their entirety. As described therein, NTP is upregulated and produced during cell death. Thus, dead and dying nerve cells are described as overproducing NTP, and accordingly, its presence indicates the death of nerve cells and the onset of Alzheimer's disease (AD).
Other species of neural thread protein have been identified as other products of the AD7c-NTP gene (e.g. a 112 amino acid protein described in NCBI Entrez-Protein database Accession #XP—032307 PID g15928971) or as being similar to neural thread proteins (e.g. a 106 amino acid protein described in NCBI Entrez-Protein database Accession #AAH14951 PID g15928971, another 106 amino acid protein described in NCBI Entrez-Protein database Accession #XP—039102 PID g18599339 and a 61 amino acid protein described in NCBI Entrez-Protein database Accession #AAH02534 PID g12803421).
Neural thread protein is associated with AD and NTP is upregulated in association with cell death in AD. AD7c-NTP mRNA is upregulated in AD brain compared to controls; AD7c-NTP protein levels in brain and in CSF are higher in AD than controls; and AD7c-NTP immunoreactivity is found in senile plaques, in neurofibrillary tangles (NFT), in degenerating neurons, neuropil threads, and dystrophic neurotic sprouts in AD and Down syndrome brains (Ozturk et al., Proc. Natl. Acad. Sci. USA, 86:419-423 (1989); de la Monte et al., J. Clin. Invest., 86(3):1004-13 (1990); de la Monte et al., J. Neurol. Sci., 113(2):152-64 (1992); de la Monte et al., Ann. Neurol., 32(6):733-42 (1992); de la Monte et al., J. Neuropathol. Exp. Neurol., 55(10):1038-50 (1996), de la Monte et al., J. Neurol. Sci., 138(1-2):26-35 (1996); de la Monte et al., J. Neurol. Sci., 135(2):118-25 (1996); de la Monte et al., J. Clin. Invest., 100:3093-3104 (1997); and de la Monte et al., Alz. Rep., 2:327-332 (1999)). NTP is localized within cells, within fine processes within the neuropil, or is extracellular in both AD and Down's Syndrome brains. de la Monte et al., Ann. Neurol., 32(6):733-42 (1992).
Elevated levels of AD7c-NTP protein have been found in both CSF and urine of AD patients (de la Monte and Wands, Front Biosci 7: 989-96 (2002); de la Monte and Wands, Journal of Alzheimer's Disease 3: 345-353 (2001); Munzar et al, Alzheimer's Reports 4: 61-65 (2001); Kahle et al, Neurology 54: 1498-1504 (2000); Munzar et al, Alzheimer Reports 3: 155-159 (2000); de la Monte et al, Alzheimer's Reports 2: 327-332 (1999); and de la Monte et al, J Clin Invest 100: 3093-3104 (1997).
Over-expression of NTP also has been linked to the process of cell death in Alzheimer's disease (de la Monte and Wands, J. Neuropathol. Exp. Neurol., 60:195-207 (2001); de la Monte and Wands, Cell Mol Life Sci 58: 844-49 (2001). AD7c-NTP has also been identified in Down's Syndrome brain tissue (Wands et al., International Patent Publication No. WO 90/06993; de la Monte et al, J Neurol Sci 135: 118-25 (1996); de la Monte et al., Alz. Rep., 2:327-332 (1999)). There is some evidence that over-expression of NTP also may be associated with normal tension glaucoma (Golubnitschaja-Labudova et al, Curr Eye Res 21: 867-76 (2000)).
NTP has proven to be an effective agent for causing cell death both in vitro in glioma and neuroblastoma cell cultures and in vivo in normal rodent muscle tissue, subcutaneous connective tissue, and dermis, and in a variety of different human and non-human origin tumors, including mammary carcinoma, skin carcinoma and papilloma, colon carcinoma, glioma of brain, and others in rodent models. See the pending U.S. patent application Ser. No. 10/092,934, entitled: Methods of Treating Tumors and Related Conditions Using Neural Thread Proteins, filed on Mar. 8, 2002.
Throughout this description, including the foregoing description of related art, any and all publicly available documents described herein, including any and all U.S. patents, are specifically incorporated by reference herein in their entirety. The foregoing description of related art is not intended in any way as an admission that any of the documents described therein, including pending United States patent applications, are prior art to the present invention.
There remains a need in the art for new, less toxic treatments for treating unwanted cellular elements. The present invention satisfies these needs.